Pills now work nicely and navbar-nav is excluded with pills / tabs.

navbar-nav doesn't work nicely with nav-pills / nav-stacked. I'm not sure if this is the right way to implement it, but navbar-nav should be excluded when the menu is a tab / pill.
Merge pull request #98 from sekjun9878/patch-1

Pills now work nicely and navbar-nav is excluded with pills / tabs.